This invention relates generally to infrared detection systems and more particularly to infrared detection systems adapted for use in the discrimination of ground targets, such as tanks, from ground clutter.
As is known in the art, passive infrared guidance systems have been used in air-to-air missiles to provide guidance signals for such missiles to enable them home on the extremely hot exhaust of jet aircraft silhouetted against a cold blue sky. The small, sharply defined exhaust plume is easily discriminated from the more gently varying sky radiation by use of a fan-blade reticle modulating the energy focused on a single infrared detector, for example.
The air-to-surface environment is, however, not nearly so benign as this air-to-air environment. Here, cultural scene elements more nearly approximate target signatures, particularly tank target signatures, resulting in the need for more sophisticated implementations and discriminants in order to provide sufficient contrasts so that acquisition and tracking of such tank targets may be achieved in the relatively cluttered surface environment.